For treating a medical condition, such as a diseased tissue present in an esophageal or spinal tumor, a failing heart valve, or cancerous lungs, surgeons may need to gain direct access to a thoracic cavity of a patient to perform surgery. Typically, surgeons gain access by performing open-chest procedures where the patient's sternum is split and separated for organ exposure. While this technique has provided surgeons with sufficient visualization of target organs in the thorax, it is extremely invasive and can cause the patient to suffer through a painful and prolonged post-surgical recovery.
There exist some minimally invasive techniques for thoracic access that are less disruptive to a patient's body. Thoracotomy procedure is one of the minimally invasive techniques that is widely performed on hundreds of thousands of people each year worldwide. In a thoracotomy procedure, the surgeon gains access to the inner thoracic cavity by physically separating the patient's ribs to create an opening into the thorax through which tools and video scopes can be passed through during the surgery. To perform the thoracotomy procedure, the surgeon may make a lateral skin incision on the patient's torso to expose the underlying chest wall. Subsequently, the surgeon may laterally cut the intercostal muscle or remove it from one of the ribs to create a space between the ribs that can be opened physically with a thoracic retraction device. Once the retraction device is installed in the incision, the surgeon can manually open the space using the hand-operated retraction device. The most common opening mechanism includes a Finochietto rack-and-pinion gear system that retracts the blades a fixed incremental distance per handle turn.
These retractors, which are also used for sternotomies have been successful in creating visual access for the surgeons but have always been the primary source for significant pain and complications that nearly half of all thoracotomy patients experience for months after their procedures. A neurovascular bundle in humans and large mammals runs along the bottom edge of each rib. Disturbance and damage to the intercostal nerve is nearly inevitable in every thoracotomy procedure and physical compression of the intercostal nerve by retractors is the leading cause of patients to experience painful breathing for a significant period of time after the surgery.
The tissue engaging structures, referred to as blades, for typical thoracic retraction devices (or retractors) are typically constructed of surgical grade stainless steel. The blades of these retractor usually have a flat planar surface, which can be continuous or fenestrated. When the flat blades press against the intercostal tissue during retraction, high concentrations of mechanical stress occur at the distal ends of the metal blade. At these distal ends of the blade, the tissue pivots and bends over the middle surface of the blade. The concentration of stress at the distal ends of the blades can be so great that not only does the intercostal nerve get crushed at these local points, but the patient may experience one or more rib fracturing at these same points. The negative consequences of this problem are not only felt by the patients. The significant nerve damage and rib fractures that the patients experience can be detrimental to the cost-saving interests of the hospitals during the acute phase of the cycle of care for the patients.
In view of the foregoing, there is a need for improved retraction devices and methods.